Field of the Invention
The present invention relates to a printing apparatus, a control method of the printing apparatus, and a non-transitory storage medium.
Description of the Related Art
In a printing apparatus such as a printer, a copying machine, or a facsimile apparatus, a printhead prints, for example, an image based on image data on a printing medium supplied from a feeding unit. As the printing medium, rolled continuous sheet, a cut sheet, a plastic sheet, or the like is generally used. In particular, a printing apparatus using a continuous sheet, which handles a printing medium of large size, generally includes a cutting mechanism that cuts the continuous sheet at a predetermined position after printing.
If the continuous sheet cut by the cutting mechanism is extremely short, like a strip, end buckling at the start of cutting or jamming of the strip into the apparatus caused by movement of the cutting mechanism may occur, resulting in incomplete cutting. In addition, if the cut continuous sheet is extremely short, the cut continuous sheet may remain in the printing apparatus without being discharged from the apparatus. To prevent such a cutting failure or discharge failure, the printing apparatus sets a minimum cut length that is a minimum length necessary when cutting the continuous sheet by the cutting mechanism. Japanese Patent No. 3826999 discloses a technique of, when cutting a continuous sheet by a cutting mechanism, adding a margin to an image to forcibly increase the length of the cut continuous sheet to the minimum cut length if an image printed by the printhead is shorter than the minimum cut length.
In recent years, technologies to implement printing without margins on the four sides of a printed product (to be referred to as a “marginless printing” hereinafter) and printing with margins on the four sides of a printed product (to be referred to as a “bordered printing” hereinafter) have been developed. In marginless printing, printing is performed within the range more than the continuous sheet width in the main scanning direction of the printhead, which is the widthwise direction of the continuous sheet, thereby forming a printed image without margins at the two ends of the continuous sheet in the widthwise direction. Additionally, in marginless printing, image printing is started after the continuous sheet is fed in an extra amount in its conveyance direction. As soon as the image printing start position of the continuous sheet reaches the cutting position of the cutting mechanism, the cutting mechanism cuts the portion fed in the extra amount and part of the image.
This makes it possible to form a printed image without a margin at the leading edge of the continuous sheet. Note that the action of cutting the fed portion and the part of the image for marginless printing will be referred to as leading edge trimming cut. In the leading edge trimming cut, the continuous sheet including the fed portion and the part of the image is cut. A setting is done such that the total length of the fed portion and the part of the image of the continuous sheet becomes a leading edge trimming cut length. The leading edge trimming cut length is set to be equal to or more than at least the minimum cut length due to the above-described reason.
In marginless printing, image printing is continuously done on the continuous sheet. When the printing edges are at the trailing edge of the image in the conveyance direction, the printing edge portion is conveyed to the cutting position. The continuous sheet is cut by the cutting mechanism with part of the image left on the continuous sheet. The cut continuous sheet thus changes to a cut sheet, and a printed image without a margin on any of the four sides can be formed. The printing apparatus waits until reception of the next printing instruction in a state in which the part of the image is left on the continuous sheet.
Control of a printing apparatus according to related art will be described here with reference to FIG. 7 assuming a case in which marginless printing in a length shorter than a minimum cut length Lc is performed, and after that, marginless printing in a length longer than the minimum cut length Lc is continuously performed. Note that the positions of broken lines in FIG. 7 indicate a plurality of cutting positions Ca, Cb, Cc, and Cd at which continuous sheet 1 is cut. An arrow Y in FIG. 7 indicates the conveyance direction Y of the continuous sheet 1. The continuous sheet 1 is conveyed from the upstream side on the upper side of FIG. 7 to the downstream side on the lower side. First, upon receiving a marginless printing instruction for a first image 20b of a length Lb shorter than the minimum cut length Lc, the printing apparatus (not shown) adds a first leading edge fed portion 30b for leading edge trimming cut to the leading edge of the continuous sheet 1 in the conveyance direction Y. Next to the first leading edge fed portion 30b, the printing apparatus adds part of the first image 20b to the continuous sheet 1 and then sets the first cutting position Ca. Here, the length from the leading edge to the continuous sheet 1 to the first cutting position Ca becomes at least the minimum cut length Lc.
Since the first image 20b after the first cutting position Ca is shorter than the minimum cut length Lc, the printing apparatus adds a trailing edge margin 32 following the first image 20b to the continuous sheet 1, and sets the second cutting position Cb. The length between the cutting positions Ca and Cb, including the part of the first image 20b and the trailing edge margin 32, thus becomes at least the minimum cut length Lc. Next, upon receiving a marginless printing instruction for a second image 20a of a length La longer than the minimum cut length Lc, the printing apparatus sets the third cutting position Cc. The third cutting position Cc is set after a second leading edge fed portion 30a for leading edge trimming cut and part of the second image 20a are added to the continuous sheet 1 after the second cutting position Cb. The length between the cutting positions Cb and Cc becomes at least the minimum cut length Lc. Since the second image 20a after the third cutting position Cc is longer than the minimum cut length Lc, the printing apparatus adds the rest of the second image 20a to the continuous sheet 1, and sets the fourth cutting position Cd near the trailing edge of the second image 20a. 
As described with reference to FIG. 7, when performing marginless printing, the printing apparatus adds the leading edge fed portions 30a and 30b to the continuous sheet 1 to do leading edge trimming cut. The leading edge fed portions 30a and 30b are unnecessary for the user. In addition, when the first image 20b of the length shorter than the minimum cut length Lc is cut into a cut sheet between the cutting positions Ca and Cb, the printed product is discharged while including the first image 20b and the trailing edge margin 32 from the leading edge in the conveyance direction Y.
The printed product of the cut sheet includes the trailing edge margin 32 and does not therefore meet the user's requirement of the final form of the printed product. Hence, the forcibly added trailing edge margin 32 needs to be cut by, for example, post-processing on the user side, and the cut trailing edge margin 32 is unnecessary. In particular, the trailing edge margin 32, with which the printed product is cut into a cut sheet between the cutting positions Ca and Cb obtains the minimum cut length Lc, and the second leading edge fed portion 30a for leading edge trimming cut of the second image 20a are discharged without being used for printing. Hence, plain portions unnecessary for the user are individually continuously generated, wastefully consuming the continuous sheet 1.